Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Amplitude modulation (AM) broadcasting is a process of radio broadcasting that was the first method of impressing sound on a radio signal and is still widely used today. As known to one ordinary skill in the art, AM broadcasting signal has low immunity from interfering signals. As shown in FIG. 1, during an AM signal travel from a broadcasting antenna tower 102 to an AM receiver antenna 104 coupled to an AM broadcast receiving device or apparatus 106, many possible noise signals may become add-on or interference signals to the original AM signal. These interference noise signals can be generated by a number of sources, such as power-line noise, lightning, other wireless communications, etc. . . . . These interference noise signals are captured together with the AM broadcast signal by the receiver circuit to become an in-band noise.
In the case, for example, when AM broadcast receiving apparatus 106 is installed in a car, electrical motor noise and electromagnetic interferences generated by the car's electrical circuits/devices may increase the noise interference to the original AM broadcast signal.
Therefore, there is a need for a system and method that can help minimize AM broadcast interferences caused by noise signals.